Usage of Open Watcom's WD for 16-bit Assembly

  1. About WD

  WD allows symbolic debugging of DOS programs, if the compiler/assembler
  and linker is able to produce Codeview debugging information. WD
  understands more formats, but these aren't relevant here.

  2. Installation

  Just copy all files contained in this package to a directory. This
  directory must be contained in the PATH environment variable when WD is
  launched. If this isn't feasible, you'll have to copy the application 
  thas is to be debugged into the directory where WD resides.

  3. Modifications

  This version of WD is not quite the standard one that one receives when
  downloading the DOS version of Open Watcom. A few files have been modified;
  in detail:

  a) MADX86.MAD: 
     - page swap in "trace" mode whenever an INT instruction is detected.

  b) STD.TRP: 
     - allows to view and edit the XMM registers.
     - interrupt flag is enabled on debuggee's entry.

  c) DEFAULT.DBG: 
     - initially shows the register window at the upper right corner -
       quite appropriate for assembly programs.

  4. Usage

  Sample DOS2.asm is provided, to make the interested audience aware of a few
  quirks of WD if assembly language programs are to be debugged and how to
  avoid the unexpected results that the quirks may cause. File MAKEDOS2.BAT
  shows how to create DOS2.EXE, including codeview symbolic debugging info.

  Once DOS2.EXE is created, just start WD with:
  
  WD DOS2.EXE

  and the debugger will stop at the 'main' procedure.

  It should be mentioned that the help file WD.HLP, which is contained
  in this package, is a Windows help file - and hence no help can
  be displayed from inside the debugger.

  japheth